The present invention is directed to a door member, and more specifically, to a door member having compression molded fiberglass door skins.
Door members have been manufactured from solid wood slabs for many years. However, solid wood door members have many disadvantages. For instance, solid wood door members can experience significant dimensional changes with variations in temperature and humidity. This can result in cracking and splitting. Also, maintenance of finishes is crucial to preventing degradation of the wood materials. In response, many consumers began using doors manufactured from more durable and dimensionally stable materials.
Recent engineering changes in wood doors have made use of laminated wood materials and thin surface veneers in an attempt to overcome the disadvantages associated with solid wood door members. However, new problems with delamination of the veneers, substrate dimensional changes, as well as continuing finishing maintenance are compounded by increased costs of wood products. This has resulted in door member products that lack consumer acceptance. Thus, the market shares of solid and laminated wood entry doors have continued to decrease.
Steel doors, which superseded wood doors in the market place, hold the majority share of the market, due mostly in part to their low cost relative to wood doors. Steel doors also have the advantage over doors made of solid and laminated wood materials of having greater insulation efficiency. Steel doors, however, have many undesirable characteristics. For instance, steel doors dent readily during construction and homeowner use. Moreover, the surfaces of the steel doors rust, especially when in service at houses in relative close proximity to salt water, and feel cold to the touch during cold weather conditions.
Fiberglass door members comprising fiberglass reinforced compression molded skins have recently become a door member product that has acquired consumer acceptance. Manufacture of these door members is known in the art; for example, U.S. Pat. Nos. 4,550,540; 4,720,951; and 5,537,789, which are incorporated herein by reference. Fiberglass door members typically comprise a door-shaped wooden frame member, a polymeric foam-type core positioned within the frame member, a first fiberglass reinforced compression molded door skin secured to a first side of the frame member, and a second fiberglass reinforced compression molded door skin secured to a second side, opposite the first side, of the frame member. The fiberglass reinforced compression molded door skins are prepared from a molding compound.
The fiberglass door members compare favorably to wood material doors in that they are less expensive than wood material doors. Moreover, fiberglass door members overcome the cracking, splitting, delaminating veneers and poor insulating efficiency associated with wood doors. Furthermore, these fiberglass door members compare favorably to steel doors in that they resist the denting, rusting and do not have the cold feel associated with steel doors. However, these fiberglass door members have, up until now, not been able to be made to have an exterior surface as smooth as steel doors or sanded wood doors.
Steel door exterior surfaces are relatively smooth and produce the appearance of a smooth exterior surface when painted. Wood doors, while having relatively coarse exterior surfaces, are sandable, before being painted, to produce the appearance of a smooth exterior surface when painted. The molded door skins of the prior art fiberglass door members have been molded to have exterior surfaces which have a very coarse wood grain pattern to simulate the appearance of a wood door when stained. However, these prior art fiberglass door members, when painted, have the appearance of a painted, unsanded, relatively coarse wood door member.
Many consumers do not find the appearance of such painted fiberglass door members aesthetically pleasing. Since, the exterior surface of a fiberglass door member cannot be sanded to produce a smooth surface, these consumers purchase wood doors or steel doors if they desire a painted door having a relatively smooth appearance. An apparent solution might seem to be to mold the door skins in a mold having smooth faces to produce door skins having smooth exterior surfaces. However, this has not proven to be a solution because the prior art molding compounds are not capable of producing a surface smooth enough to simulate painted steel or sanded wood doors, when painted, due to surface variations created in the molding process caused by shrinkage of the molded part.
Accordingly, it is believed that if a fiberglass door member could be manufactured to simulated steel door members and sanded wood members, when painted, that certain consumer preference for steel door or wood members would shift to fiberglass door members. Thus, there is a need for a fiberglass door member that has a smooth enough surface to simulate steel and wood door members when painted.
The present invention is a door member comprising a frame having a first side and a second side, opposite the first side, a core positioned within the frame, and a molded skin attached to the frame. The skin is prepared from a molding compound which, when molded, has a shrinkage of between about xe2x88x920.0003 to about +0.0015. The molding compound comprises a resin system comprising a curable polyester resin, a co-curable unsaturated monomer, and at least two low profile additives. The molding compound further includes at least about 30 percent by weight, based on the weight of the molding compound, of filler material, and less than about 35 weight percent, based on the weight of the molding compound, of fibrous reinforcement.
An object of the present invention is to provide a fiberglass door member that has a smooth enough surface to simulate steel and wood door members when painted.
Another object of the present invention is to provide compression molded fiberglass door skins having a relatively low shrinkage when molded.
These and other objects of the present invention will become more apparent from a reading of the specification in conjunction with the drawings.